The mean is and standard deviation is
. Then the variable
.
Use substitution , then the variable
.
The probability can be calculated in the following way:
for X=80, and
. From the diagram
.
Conclusion: if 188 students take the exam, then 188·0.84=157.92 (157) would receive a score above 80
Answer:
Niles and Bob were traveling for 6 hours.
Step-by-step explanation:
The speed or rate at which an object is moving can be computed using the formula:
Here:
<em>s</em> = speed
<em>d</em> = distance traveled
<em>t</em> = time taken
It is provided that Niles and Bob sailed at the same time for the same length of time.
Speed of Niles sailboat is, <em>s</em>₁ = 6 mph.
Distance traveled by Niles' sailboat is, <em>d</em>₁ = 36 miles.
Speed of Bob's sailboat is, <em>s</em>₂ = 16 mph.
Distance traveled by Bob's sailboat is, <em>d</em>₂ = 96 miles.
It took both Niles and Bob the same time to travel the respective distance.
Compute the time it took Niles to travel 36 miles at 6 mph speed as follows:
It took Niles 6 hours to travel 36 miles at 6 mph speed.
Compute the time it took Bob to travel 96 miles at 16 mph speed as follows:
It took Bob 6 hours to travel 96 miles at 16 mph speed.
Thus, Niles and Bob were traveling for 6 hours.